Control devices for hybrid vehicles, and methods of controlling hybrid vehicles.

Abstract

Invention details;

Claims

ocr02ss1. A control device for hybrid vehicles with an engine and electric motor as power sources, capable of both series hybrid drive and direct engine drive using the engine and electric motor, and equipped with a NOx treatment system using an SCR catalytic converter and an LNT catalytic converter in the engine exhaust passage. The control device comprises: a fault detection unit that detects abnormalities in the NOx treatment system related to the LNT catalytic converter; and a drive condition control unit that, when a fault is detected, prohibits direct engine drive as the vehicle's drive mode and limits the drive mode to series hybrid drive, and operates the engine at approximately a constant engine output in such a way that the engine output equals or exceeds a predetermined threshold within an output range where NOx emissions from the engine do not exceed the amount feasible for NOx treatment by the SCR catalytic converter system.

21. Hybrid vehicle control device under Claim 1, whereby the drive-in control unit, when a malfunction is detected, operates the engine in NOx reduction mode instead of fuel efficiency priority mode.

3. Hybrid vehicle control device under Claim 2, whereby in NOx reduction mode, the engine EGR valve opening is increased to a value greater than the opening set in fuel efficiency priority mode.

4. Hybrid vehicle control device under Claim 1, where the possible NOX treatment amount of the SCR catalytic converter is calculated based on the SCR catalytic converter temperature and the SCR catalytic converter ammonia storage amount at the time the malfunction is detected.

5. Hybrid vehicle control device under Claim 1, whereby the drive-in control unit, when a malfunction is detected, operates the engine at approximately a constant engine output in such a way that the engine output is at the maximum output within the output range or at an output that is a margin greater than the maximum output. 6.The control device of the hybrid vehicle under claim 1, where, when a malfunction is detected, the engine output is used by the electric motor, and the required driving force based on the driver's acceleration operation is met using the electric motor output.

7. The control device of the hybrid vehicle under claim 1, where the malfunction is a failure mode in which it is determined that it cannot ensure the catalytic converter's treatment performance.

8. The control device of the hybrid vehicle under claim 7, where the malfunction includes a temperature malfunction of the LNT catalytic converter, and abnormal sensor values ​​and abnormal operation of the NOx sensor located upstream of the LNT catalytic converter.9.The control method for hybrid vehicles with an engine and electric motor as power sources, capable of both series hybrid and direct engine-electric drive, and featuring a NOx treatment system using an SCR catalytic converter and an LNT catalytic converter in the engine exhaust system, comprises: Step one, detecting malfunctions in the NOx treatment system related to the LNT catalytic converter; and step two, prohibiting direct engine drive as the vehicle's driving mode, limiting the drive mode to series hybrid drive, and operating the engine at approximately a constant engine output in such a way that the engine output equals or exceeds a predetermined value within an output range where engine NOx emissions do not exceed the amount feasible for NOx treatment by the SCR catalytic converter system. Step two is implemented when a malfunction is detected in step one.

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